Comparison of the nutrient value of clipped and esophageal dietary samples of cattle grazing Lehmann lovegrass (Eragrostis Lehmanniana, nees)

Abstract

Two trials were conducted to demonstrate diet selected by grazing cattle. Selection criteria were investigated on the basis of cattle selection for plant species, green leaf in preference to dry leaf or dry stem and the chemical contents of esophageal samples versus those in the standing crop. The influence of residual old vegetation on selection ability was studied by mowing all or part of the pasture. Cattle consumed Lehmann lovegrass in preference to shrubby species (Table 1). The esophageal samples contained higher levels of protein, phosphorus and IVDMD than that in the standing crop in both Trial 1 and Trial 2. Neutral detergent fiber was higher in the standing crop than in the esophageal samples, whereas in Trial 2, there appeared to be no difference in NDF. Removal of old vegetation by mowing had no effect on selection for plant parts. Cattle selected green leaf, in preference to dry leaf or dry stem regardless of the presence of old material. Free ranging cattle selected a diet that was higher in nutrient density and more digestible than the available forage.